Re: Redesigning a new PROM for //e and //c hardware

[mspangler@gemsi.com]

On Monday, November 5, 2012 4:23:34 AM UTC-8, Benoit0123 wrote:

> My asking is for the existence of a project which goal is to rewrite the
> 
> PROM content, by "refactoring" Applesoft code so that this code could
> 
> benefit for a potential enhanced CPU within the host (either CMOS 65C02 or a
> 
> 65802).
> 
> The code space reduction could benefit for implementing more features for
> 
> the monitor or for Applesoft itself.

The debug ROM is available out there somewhere. I found a copy, but I'm not sure where at this point. 

I was undertaking a project to make the IIe rom do proper disassembly of  65C02 code. I mostly succeeded, but finding the room was quite an exercise. I had to replace the slot-3 check, and do some fancy vectoring. In the enhanced IIe ROM the disassembler is scattered all over. 

That was the second half of the project. The first half was to put several of the Beagle Basic routines in ROM to replace the cassette port routines. I have the Else, Tone, Swap, and a Repeat Until (which was not Beagle Basic), and I converted USR() to readkey to save having to peek whatever that was. There was also enough room to have Timer (or Wait) but then I had to sacrifice Flash to get a spare token. 

The changes to the token lookup table broke Program Writer,  but GPLE still seemed to work.